Three dimensional co-registration for intravascular diagnosis and therapy

Abstract

A method and system are disclosed for creating, in a coordinated manner, graphical images of a body including vascular features from a combination of image data sources. The method includes initially creating an angiographic image of a vessel segment. The angiographic image is, for example, either a two or three dimensional image representation. Next, a vessel image data set is acquired that is distinct from the angiographic image data. The vessel image data set comprises information acquired at a series of positions along the vessel segment. An example of such vessel image data is a set of intravascular ultrasound frames corresponding to circumferential cross-section slices taken at various positions along the vessel segment. The angiographic image and the vessel image data set are correlated by comparing a characteristic rendered independently from both the angiographic image and the vessel image data at positions along the vessel segment.

1. A method, comprising:
 obtaining angiographic image data of a vessel segment from an imaging device positioned external to the vessel segment; 
 creating a three-dimensional image of the vessel segment based upon the obtained angiographic image data; 
 obtaining intravascular ultrasound (IVUS) image data of the vessel segment from an imaging device positioned within the vessel segment, wherein the IVUS image data comprises a series of intravascular images acquired as the imaging device positioned within the vessel segment is moved through and along the vessel segment; 
 correlating IVUS image data to the three-dimensional image of the vessel such that each of the images of the series of intravascular images of the IVUS image data is correlated to a portion of the three-dimensional image of the vessel created based upon the obtained angiographic image data, wherein correlating the IVUS image data to the three-dimensional image of the vessel includes aligning the images of the series of intravascular images of the IVUS image data both axially and circumferentially to the corresponding portions of the three-dimensional image of the vessel, wherein the images of the series of intravascular images of the IVUS image data are axially aligned with the three-dimensional image of the vessel by determining a best axial fit between a lumen measurement of the vessel segment as depicted in the images of the series of intravascular images of the IVUS image data and a lumen measurement of the vessel segment as depicted in the three-dimensional image of the vessel segment based on the obtained angiographic image data, and wherein the images of the series of intravascular images of the IVUS image data are circumferentially aligned with the three-dimensional image of the vessel after the images of the series of intravascular images of the IVUS image data are axially aligned with the three-dimensional image of the vessel and wherein the images of the series of intravascular images of the IVUS image data are circumferentially aligned with the three-dimensional image of the vessel by determining a best angular fit between a lumen measurement of the vessel segment as depicted in the images of the series of intravascular images of the IVUS image data and a lumen measurement of the vessel segment as depicted in the three-dimensional image of the vessel segment based on the obtained angiographic image data; 
 rendering simultaneously on a display an image of the series of intravascular images of the IVUS image data and at least the correlated portion of the three-dimensional image of the vessel as determined by the correlating step; 
 wherein the lumen measurement is a cross-sectional area; and 
 wherein determining the best axial fit between the cross-sectional area of the vessel segment as depicted in the images of the series of intravascular images of the IVUS image data and the cross-sectional area of the vessel segment as depicted in the three-dimensional image of the vessel segment based on the obtained angiographic image data comprises determining a minimum of the sum of the squared differences between the cross-sectional area of the vessel segment as depicted in the images of the series of intravascular images of the IVUS image data and the cross-sectional area of the vessel segment as depicted in the three-dimensional image of the vessel segment based on the obtained angiographic image data. 
 
     
     
       2. The method of  claim 1 , wherein time vectors of the series of intravascular images and a pullback speed of the imaging device are utilized to axially align the images of the series of intravascular images of the IVUS image data with the three-dimensional image of the vessel. 
     
     
       3. The method of  claim 1 , wherein determining the best axial fit between the cross-sectional area of the vessel segment as depicted in the images of the series of intravascular images of the IVUS image data and the cross-sectional area of the vessel segment as depicted in the three-dimensional image of the vessel segment based on the obtained angiographic image data comprises determining a minimum of 
       
         
           
             
               
                 
                   ∑ 
                   
                     n 
                     = 
                     1 
                   
                   N 
                 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 
                   
                     ( 
                     
                       
                         A 
                         IVUS 
                       
                       - 
                       
                         A 
                         Angio 
                       
                     
                     ) 
                   
                   2 
                 
               
               , 
             
           
         
       
       where A IVUS  is the cross-sectional area of the vessel as depicted in images 1 to N of the series of intravascular images of the IVUS image data and A Angio  is the cross-sectional area of the vessel as depicted in the three-dimensional image of the vessel segment based on the obtained angiographic image. 
     
     
       4. The method of  claim 1 , wherein axially aligning the images of the series of intravascular images of the IVUS image data with the three-dimensional image of the vessel includes applying a skewing displacement. 
     
     
       5. The method of  claim 1 , wherein axially aligning the images of the series of intravascular images of the IVUS image data with the three-dimensional image of the vessel includes applying a warping displacement. 
     
     
       6. The method of  claim 1 , wherein circumferentially aligning the images of the series of intravascular images of the IVUS image data with the three-dimensional image of the vessel includes rotating the images of the series of intravascular images of the IVUS image data based on a best angular fit. 
     
     
       7. The method of  claim 6 , wherein the best angular fit is determined for a plurality of the images of the series of intravascular images of the IVUS image data. 
     
     
       8. The method of  claim 6 , wherein the best angular fit is determined for each of the images of the series of intravascular images of the IVUS image data. 
     
     
       9. The method of  claim 6 , wherein a degree of rotation between adjacent images of the series of intravascular images of the IVUS image data is limited. 
     
     
       10. The method of  claim 9 , wherein the degree of rotation between adjacent images of the series of intravascular images of the IVUS image data is limited by a spline fit. 
     
     
       11. The method of  claim 9 , wherein the degree of rotation between adjacent images of the series of intravascular images of the IVUS image data is limited by a cubic polynomial fit. 
     
     
       12. The method of  claim 1 , wherein each of the images of the series of intravascular images of the IVUS image data is correlated to a portion of the three-dimensional image of the vessel created based upon the obtained angiographic image data in a live mode. 
     
     
       13. The method of  claim 12 , wherein the angiographic image data and the IVUS image data are obtained simultaneously. 
     
     
       14. The method of  claim 1 , wherein each of the images of the series of intravascular images of the IVUS image data is correlated to a portion of the three-dimensional image of the vessel created based upon the obtained angiographic image data in a playback mode. 
     
     
       15. The method of  claim 14 , wherein the angiographic image data and the IVUS image data are obtained simultaneously. 
     
     
       16. The method of  claim 1 , wherein the angiographic image data and the IVUS image data are obtained simultaneously. 
     
     
       17. The method of  claim 16 , further comprising aligning the imaging device positioned external to the vessel segment with the imaging device positioned within the vessel segment using at least one fiduciary point. 
     
     
       18. The method of  claim 17 , wherein the at least one fiduciary point is a marker associated with the imaging device positioned within the vessel segment. 
     
     
       19. The method of  claim 18 , wherein the marker is a radiopaque marker. 
     
     
       20. The method of  claim 18 , wherein the marker is an electrode. 
     
     
       21. The method of  claim 1 , further comprising treating a portion of the vessel using the simultaneously rendered image of the series of intravascular images of the IVUS image data and at least the correlated portion of the three-dimensional image of the vessel for visual guidance. 
     
     
       22. The method of  claim 21 , wherein treating the portion of the vessel comprises placing a stent. 
     
     
       23. The method of  claim 1 , wherein the step of rendering simultaneously on a display an image of the series of intravascular images of the IVUS image data and at least the correlated portion of the three-dimensional image of the vessel as determined by the correlating step includes overlaying the image of the series of intravascular images of the IVUS image data onto the correlated portion of the three-dimensional image of the vessel. 
     
     
       24. The method of  claim 1 , wherein the step of rendering simultaneously on a display an image of the series of intravascular images of the IVUS image data and at least the correlated portion of the three-dimensional image of the vessel as determined by the correlating step includes displaying a maximum thickness line and a minimum thickness line on the three-dimensional image of the vessel based on the IVUS image data. 
     
     
       25. A method, comprising:
 obtaining angiographic image data of a vessel segment from an imaging device positioned external to the vessel segment; 
 obtaining intravascular ultrasound (IVUS) image data of the vessel segment from an imaging device positioned within the vessel segment, wherein the IVUS image data comprises a series of intravascular images acquired as the imaging device positioned within the vessel segment is moved through and along the vessel segment, wherein the IVUS image data is obtained simultaneously with the angiographic image data; 
 correlating IVUS image data to the angiographic image data of the vessel such that each of the images of the series of intravascular images of the IVUS image data is correlated to a portion of the angiographic image data, wherein correlating the IVUS image data to the angiographic image data includes aligning the images of the series of intravascular images of the IVUS image data both axially and rotationally to corresponding portions of the angiographic image data, wherein the images of the series of intravascular images of the IVUS image data are axially aligned with the three-dimensional image of the vessel by determining a best axial fit between a lumen measurement of the vessel segment as depicted in the images of the series of intravascular images of the IVUS image data and a lumen measurement of the vessel segment as depicted in the angiographic image data, and wherein the images of the series of intravascular images of the IVUS image data are rotationally aligned with the angiographic image data by determining a best angular fit between a lumen measurement of the vessel segment as depicted in the images of the series of intravascular images of the IVUS image data and a lumen measurement of the vessel segment as depicted in the angiographic image data; 
 displaying simultaneously at least one image of the series of intravascular images of the IVUS image data and at least the correlated portion of the angiographic image data as determined by the correlating step; 
 wherein the lumen measurement is a cross-sectional area; and 
 wherein determining the best axial fit between the cross-sectional area of the vessel segment as depicted in the images of the series of intravascular images of the IVUS image data and the cross-sectional area of the vessel segment as depicted in the three-dimensional image of the vessel segment based on the obtained angiographic image data comprises determining a minimum of the sum of the squared differences between the cross-sectional area of the vessel segment as depicted in the images of the series of intravascular images of the IVUS image data and the cross-sectional area of the vessel segment as depicted in the three-dimensional image of the vessel segment based on the obtained angiographic image data. 
 
     
     
       26. The method of  claim 25 , wherein the step of obtaining angiographic image data includes obtaining a two-dimensional angiographic image data. 
     
     
       27. The method of  claim 25 , wherein displaying simultaneously at least one image of the series of intravascular images of the IVUS image data and at least the correlated portion of the angiographic image data as determined by the correlating step includes overlaying the at least one image of the series of intravascular images of the IVUS image data onto the correlated portion of the three-dimensional image of the vessel.